Extensive use has been and is being made of cards which bear data on a stripe of magnetized material. Such cards, for example, find application as credit cards and bank cards which permit the card user to facilitate credit and banking transactions, and identification badges which permit the card user to obtain access to a facility.
Typically, such cards include a plastic substrate, with the stripe of magnetized material being located on one of the major surfaces of the substrate. Data is read from the stripe by producing relative motion between the card and a magnetic reading head located in a magnetic card reader, with the magnetic reading head providing appropriate electrical signals representing the data to a signal processing apparatus forming part of a computer terminal or other apparatus.
Due to the fact that a card may be reused a considerable number of times, the card often becomes warped, or otherwise deformed in directions transverse to its major surfaces. To minimize errors in data reading that would otherwise occur, the stripe must be maintained in close proximity to the magnetic reading head for its entire length as the card is moved relative thereto. In addition, the card should be moved at a relatively uniform velocity with respect to the magnetic reading head.
The magnetic card readers of the prior art generally utilize some sort of mechanism for effecting relative motion between the card and the magnetic reading head and for exerting substantial pressure on the card during such motion to maintain the stripe in proximity to the magnetic reading head. For example, a common type of prior art magnetic reader includes sets of counterrotating, motor-driven rollers at the entrance to and at the exit from a card reading station including a magnetic reading head, with the rollers rotating at a substantial constant velocity and with the stripe being pressed against a surface of the magnetic reading head by a spring-biased member which bears against the major surface of the card opposite from that on which the stripe is located. As another example, magnetic readers are known to the prior art which utilize a single, resilient, motor-driven roller opposing the magnetic reading head, the roller being driven at a substantially constant velocity.
Although the prior art magnetic card readers generally provide acceptable operation in reading data from warped or otherwise deformed cards, they are subject to certain disadvantages. The mechanisms that are provided for card transport and for pressure application upon the card are generally complex in construction and operation and utilize many parts. Accordingly, such readers are expensive to construct and to maintain, and are additionally subject to failures when particularly used in hostile environments in which dust, dirt or grease is prevalent. The mechanisms are, for the most part, bulky so that the card readers cannot be utilized in many situations where space is at a premium. Further, the mechanisms require an external source of power for their operation and are therefore energy-inefficient.
It is therefore an object of this invention to provide an manually operable magnetic card reader which does not require an external source of power.
It is a further object of this invention to provide such a reader which is simple in its construction and operation, which utilizes a minimum number of parts, and which is compact, and which is therefore easy and inexpensive to construct, install and maintain.
It is yet a further object of this invention to provide such a reader which is rugged in its construction and which is accordingly not likely to fail when used in hostile environments.
It is another object of this invention to provide a magnetic head assembly for such a reader which is capable of providing reliable reading of data from a card bearing a stripe of magnetized material, irrespective of whether the card has been warped or otherwise deformed.
It is yet another object of this invention to provide a magnetic head assembly such a reader which permits the card to be manually moved relative to a magnetic reading head of the reader at a relatively uniform velocity.